Author: Tom Nardi

With the cost of 3D printers dropping rapidly, we’ve started to see a trend of hackers re-purposing them for various tasks. It makes perfect sense; with the hotend and extruder turned off (or removed entirely), you’ve got a machine that can move a tool around in two or three dimensions with exceptional accuracy. Printers modified to carry lasers, markers, and even the occasional rotary tool, are becoming a common sight in our tip line.

Last year [Matthew Rayfield] attached a marker to his 3D printer and had it sketch out some pictures, but recently he decided to revisit the idea and try to put a unique spin on it. The end result is a throwback to the classic dot matrix printers of yore utilizing decidedly modern hardware and software. There’s something undeniably appealing about the low-fi nature of dot matrix printing, and when fed the appropriate images this setup is capable of producing something which we’ve got to admit is dangerously close to being art.

To create these images, [Matthew] has created “Pixels-to-Gcode”, an online service that anyone can use to turn an arbitrary image into GCode they can feed their 3D printer. There’s a number of options available for you to play with so you can dial in the specific effect you’re looking for. Pointillist images can be created using a tight spacing of dots, but widen them up, and your final image becomes increasingly abstract.

The hardware side of this project is left largely as an exercise for the reader. [Matthew] has attached a fine-point pen to his printer’s head using a rubber band, but admits that it’s far from ideal. A more robust approach would be some kind of 3D printed device that allows you to quickly attach your pen or marker so the printer can be easily switched between 2D and 3D modes. We’d also be interested in seeing what this would look like if you used a laser mounted on the printer to burn the dots.

Hackaday readers are perhaps familiar with the Arduboy, an open source handheld gaming system that aims to combine the ease of Arduino development with the seething nostalgia the Internet has towards the original Nintendo Game Boy. While not quite the same as getting one of your games published for a “real” system, the open source nature of the Arduboy platform allows an individual to develop a game playable on a commercially manufactured device.

While the Arduboy hardware itself is actually quite slick, that hasn’t stopped people from trying to bring its games to other pieces of hardware. Now thanks to the efforts of [uXe], the Game Boy Advance is well on its way to becoming Arduboy compatible, in a way bringing the whole project full circle. Assuming this gadget becomes a commercial device (it sounds like that’s still up in the air), Arduboy developers will be able to proudly play their creations on the final and objectively best entry into the Game Boy line.

Getting to this point has been something of an adventure, as documented in a thread from the Arduboy forums. Members of the community wondered what it would take to get Arduboy games running on a real Game Boy, but pretty quickly it was decided that the original beige brick model wasn’t quite up to the task. Eventually its far more capable predecessor the Game Boy Advance became the development target, and different approaches were considered for getting existing games running on the platform.

While there were some interesting ideas, such as using the GBA’s link port to “feed” the system games over SPI, in the end [uXe] decided to look into creating an FPGA cartridge that would actually run the Arduboy games. In this scenario, the GBA itself is basically just being used as an interface between the FPGA and the human player. In addition to these low-level hardware considerations, there was considerable discussion about the more practical aspects of bringing the games to the new hardware, such as how to best scale the Arduboy’s 128 x 64 output to the GBA’s 240 × 160 screen.

As demonstrated in the videos after the break, [uXe] now as all the elements for playing Arduboy games on the GBA in place, including the ability to disable full screen scaling by using the shoulder buttons. Now he just needs to shrink the hardware down to the point it will fit inside of a standard GBA cartridge. Beyond that, who knows? Perhaps the appeal of being able to run Arduboy games on a real Game Boy is enough to warrant turning this hack into a new commercial product.

At the turn of the 21st century, it became pretty clear that even our cars wouldn’t escape the Digital Revolution. Years before anyone even uttered the term “smartphone”, it seemed obvious that automobiles would not only become increasingly computer-laden, but they’d need a way to communicate with each other and the world around them. After all, the potential gains would be enormous. Imagine if all the cars on the road could tell what their peers were doing?

Forget about rear-end collisions; a car slamming on the brakes would broadcast its intention to stop and trigger a response in the vehicle behind it before the human occupants even realized what was happening. On the highway, vehicles could synchronize their cruise control systems, creating “flocks” of cars that moved in unison and maintained a safe distance from each other. You’d never need to stop to pay a toll, as your vehicle’s computer would communicate with the toll booth and deduct the money directly from your bank account. All of this, and more, would one day be possible. But only if a special low-latency vehicle to vehicle communication protocol could be developed, and only if it was mandated that all new cars integrate the technology.

Except of course, that never happened. While modern cars are brimming with sensors and computing power just as predicted, they operate in isolation from the other vehicles on the road. Despite this, a well-equipped car rolling off the lot today is capable of all the tricks promised to us by car magazines circa 1998, and some that even the most breathless of publications would have considered too fantastic to publish. Faced with the challenge of building increasingly “smart” vehicles, manufacturers developed their own individual approaches that don’t rely on an omnipresent vehicle to vehicle communication network. The automotive industry has embraced technology like radar, LiDAR, and computer vision, things which back in the 1990s would have been tantamount to saying cars in the future would avoid traffic jams by simply flying over them.

In light of all these advancements, you might be surprised to find that the seemingly antiquated concept of vehicle to vehicle communication originally proposed decades ago hasn’t gone the way of the cassette tape. There’s still a push to implement Dedicated Short-Range Communications (DSRC), a WiFi-derived protocol designed specifically for automotive applications which at this point has been a work in progress for over 20 years. Supporters believe DSRC still holds promise for reducing accidents, but opponents believe it’s a technology which has been superseded by more capable systems. To complicate matters, a valuable section of the radio spectrum reserved for DSRC by the Federal Communications Commission all the way back in 1999 still remains all but unused. So what exactly does DSRC offer, and do we really still need it as we approach the era of “self-driving” cars?

At this point it’s something of a given that a member of the ESP8266 family is likely your best bet if you want to cobble together a small Internet-connected gadget. Costing as little as $3 USD, this well documented all-in-one solution really can’t be beat. But of course, the hardware is only one half of the equation. Deciding how to handle the software side of your homebrew Internet of Things device is another story entirely.

A simple Telegram ESP8266 switch

It would be fair to say that there’s no clear-cut “right” way to approach the software, and it really depends on the needs or limitations of your particular project. For example [Brian Lough] finds that building Telegram support into his ESP8266 allows him to accomplish his goals with the minimum amount of fuss while at the same time using an environment he’s already comfortable with. He recently wrote in to share one of his Telegram projects with us, and in the video after the break, takes the time to explain some of the things he likes best about controlling his hardware through the encrypted chat platform.

But you don’t have to take his word for it, you can try it yourself. Thanks to the software library that [Brian] has developed to connect his projects to Telegram, the aptly named “Universal Telegram Bot Library”, anyone can easily follow in his footsteps. Adding his Telegram library to your next ESP8266 project is as easy as selecting it in the Arduino IDE. From there the video explains the process for getting a bot ID from Telegram, and ultimately how you use it to receive messages from the service. What you do with those messages is entirely up to you.

Now that nearly every car on the road comes with an electronic key fob, people are desperate to find ways to repair these indispensable little gadgets without coughing up potentially hundreds of dollars at the dealership. There’s a whole market for replacement shells which you can transplant your (hopefully) still functional electronics into, but if you’re going to go through the trouble of putting the electronics into a new case, why not make it special?

That’s what [Michicanery] was thinking when he decided to build his own custom key fob. The end result is an utterly magnificent feat of engineering that’s sure to be a conversation for the life of the vehicle, if not beyond. Made of wood and aluminum cut on his OpenBuilds Lead CNC 1010, this build just might inspire you to “accidentally” drop your existing fob from a great height. Oh no, what a shame.

[Michicanery] starts by disassembling his original fob, which is the type that has a key integrated directly into the device. This meant his replacement would need a bit more thought put into it than a separate stand-alone fob, but at least it wasn’t one of the ones where you have to stick the whole thing into the dashboard. To make sure the build was strong enough to survive a lifetime of being turned in the ignition and generally fiddled with, he cut the central frame and buttons out of 1/4″ thick aluminum.

The top and bottom of the fob were then cut from Chechen wood and then chamfered on a table router so it felt a bit better in the hand. He applied oil to the pieces to bring out the natural color and grain of the wood, but not before engraving his own logo onto the back of the case for that extra touch of personalization. Not that we think [Michicanery] is going to have trouble identifying his keys from this point on.

By now we’ve all seen the cheap headsets that essentially stick a smartphone a few inches away from your face to function as a low-cost alternative to devices like Oculus Rift. Available for as little as a few dollars, it’s hard to beat these gadgets for experimenting with VR on a budget. But what about if you’re more interested in working with augmented reality, where rendered images are superimposed onto your real-world view rather than replacing it?

As it turns out, there are now cheap headsets to do that with your phone as well. [kvtoet] picked one of these gadgets up for $30 USD on AliExpress, and used it as a base for a more capable augmented reality experience than the headset alone is capable of. The project is in the early stages, but so far the combination of this simple headset and some hardware liberated from inexpensive Chinese smartphones looks to hold considerable promise for delivering a sub-$100 USD development platform for anyone looking to jump into this fascinating field.

On their own, these cheap augmented reality headsets simply show a reflection of your smartphone’s screen on the inside of the lenses. With specially designed applications, this effect can be used to give the wearer the impression that objects shown on the phone’s screen are actually in their field of vision. It’s a neat effect to be sure, but it doesn’t hold much in the way of practical applications. To turn this into a useful system, the phone needs to be able to see what the wearer is seeing.

To that end, [kvtoet] relocated a VKWorld S8 smartphone’s camera module onto the front of the headset. Beyond its relatively cost, this model of phone was selected because it featured a long camera ribbon cable. With the camera on the outside of the headset, an Android application was created which periodically flashes a bright LED and looks for reflections in the camera’s feed. These reflections are then used to locate objects and markers in the real world.

In the video after the break, [kvtoet] demonstrates how this technique is put to use. The phone is able to track a retroreflector laying on the couch quickly and accurately enough that it can be used to adjust the rendering of a virtual object in real time. As the headset is moved around, it gives the impression that the wearer is actually viewing a real object from different angles and distances. With such a simplistic system the effect isn’t perfect, but it’s exciting to think of the possibilities now that this sort of technology is falling into the tinkerer’s budget.

We probably don’t need to tell this to the average Hackaday reader, but we’re living in a largely disposable society. Far too many things are built as cheaply as possible, either because manufacturers know you won’t keep it for long, or because they don’t want you to. Of course, the choice if yours if you wish to you accept this lifestyle or not.

Like many of us, [Erik] does not. When the painted markings on his stove become so worn that he couldn’t see them clearly, he wasn’t about to hop off to the appliance store to buy a new one. He decided to take things into his own hands and fix the poor job the original manufacturers did in the first place. Rather than paint on new markings, he put science to work and electroetched them into the metal.

Whether or not you’ve got a stove that needs some sprucing up, this technique is absolutely something worth adding to your box of tricks. Using the same methods that [Erik] did in his kitchen, you could etch an awesome control panel for your next device.

So how did he do it? Despite the scary multisyllabic name, it’s actually quite easy. Normally the piece to be etched would go into a bath of salt water for this process, but obviously that wasn’t going to work here. So [Erik] clipped the positive clamp of a 12 V battery charger to the stove itself, and in the negative clamp put a piece of gauze soaked in salt water. Touching the gauze to the stove would then eat away the metal at the point of contact. All he needed to complete the project were some stencils he made on a vinyl cutter.